County annual report · FIPS 30027
2021 Fergus County, MT Power Outage Report
In 2021, customers in Fergus County, MT went without power for an average of 3.6 hours, a total of 20K customer-hours (Montana average 5.0 hours). That ranks 29th worst of 51 Montana counties and 1649th of 2,974 nationally.
Compared with MT, the US and 2020
Coverage line is EAGLE-I's share of Montana customers tracked each year.
Biggest outages in Fergus County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | March 29, 2021 10:45 | March 29, 2021 12:15 | 1h 30m | 377 | 566 |
| 2 | January 30, 2021 00:00 | January 30, 2021 04:30 | 4h 30m | 372 | 1,674 |
| 3 | February 22, 2021 03:30 | February 22, 2021 09:15 | 5h 45m | 372 | 2,139 |
| 4 | December 1, 2021 08:45 | December 3, 2021 21:15 | 2d 12h | 353 | 13K |
| 5 | January 22, 2021 00:30 | January 22, 2021 02:15 | 1h 45m | 166 | 290 |
| 6 | January 14, 2021 08:00 | January 15, 2021 04:15 | 20h 15m | 47 | 788 |
| 7 | January 13, 2021 22:00 | January 14, 2021 04:30 | 6h 30m | 43 | 187 |
| 8 | July 7, 2021 21:15 | July 8, 2021 02:30 | 5h 15m | 40 | 128 |
| 9 | February 22, 2021 14:45 | February 22, 2021 19:30 | 4h 45m | 39 | 47 |
| 10 | November 16, 2021 12:15 | November 16, 2021 14:45 | 2h 30m | 34 | 53 |
Outage episodes by size in 2021: 5 reached 100+ customers, 0 reached 1,000+ customers, 0 reached 10,000+ customers.
Utility reliability filed with the EIA
SAIDI (average outage time per customer) and SAIFI (average interruptions per customer) that utilities serving Fergus County reported on EIA Form 861 for 2021, or their most recent earlier filing. Utility-wide figures, not county-specific.
| Utility | EIA year | SAIDI | SAIFI | SAIDI excl. major events | SAIFI excl. major events |
|---|---|---|---|---|---|
| NorthWestern Energy LLC - (MT) | 2021 | 2.5 hrs | 1.37 | 2.1 hrs | 1.18 |
| NorthWestern Energy | - | - | - | - | - |
| Fergus Electric Coop, Inc | - | - | - | - | - |
| Hill County Electric Coop, Inc | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 76% of Montana's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 5,384 customers (ORNL modeled county customer count), including major storm days. It is comparable across counties but is not the SAIDI a utility files.
- An outage event is a continuous stretch with customers out; counts at 100, 1,000 and 10,000+ use its peak.
- Years loaded: 2015–2025. Fergus County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Fergus County, MT annual power outage report, 2021, data as of Oct 3, 2026 02:41 UTC, sources: DOE EAGLE-I (https://eagle-i.doe.gov/); EAGLE-I modeled customer counts (MCC) (https://figshare.com/); EIA Form 861 (utility reliability) (https://www.eia.gov/electricity/data/eia861/). https://massoutage.com/reports/2021/montana/fergus-county